Accuracy problems

[thisguy87]

Hi everyone, just got done assembling my first makeker 8'' i3. couldn't be happier with quality and fitment of all the parts. My only issue would be the thin theaded rods used for the Z axis, as it has more wobble than an m8, other than that, nothing short of excellent.


I have it printing but the accuracy is off. I found some info on adjusting the stepper motors by temp and I've got them all fluctuating between 92-98. The extruder stepper is currently set higher because the gears are too tight. I need to drill out the holes for the stepper motor so it can move over more, but thats a seperate problem.

i'm trying to print the calibration piece that you can fit a nickel into and its printing extremely sloppy, the circle is off and its missing spots. The spots it does get are filled in very nicely and smooth. Its just getting holes and printing innacurately.

Were using the standard settings and 0.9.9 slicer as directed in the PDF.


photo.jpg Heres the nickel calibration piece. I've gotten it alot better afew times, but still not near perfect


Thanks in advance for any help.

[old man emu]

The extruder stepper is currently set higher because the gears are too tight. I need to drill out the holes for the stepper motor so it can move over more, but thats a seperate problem.

Before you start drilling holes, try putting a bit of grease on the gear teeth.

OME

[beerdart]

We had to slot the extruder holes to free up the gear drive received and assembled early February.

[RobH2]

That's a crazy ugly print. Yikes. Looks like you have multiple problems. Have you tried printing any other calibration models? If so, do they fail the same way? Have you tried printing the standard 1" cube? Try that and post back with a photo so we can see what is happening.

I hesitate to complicate things but I started out with Slic3r but stated getting much better results with KISSlicer. It won't connect directly to the printer and you have to use the SD card method but it makes the best prints. I've experimented with Slic3r (0.9.1, 0.9.9, 1.0.0), Repetier-H, Cura 13.12 and Cura 13.11.2, KISSlicer64 and ReplicatorG. Colin at Makerfarm said that the newer Slic3r was problematic. He's apparently had issues with but it performs fine for me. I like way Slic3r interfaces with Pronterface but I still like KISSlicer best. Besides KISSSlicer I like Cura, either version. What I don't like about Slic3r is that you don't get a 3d preview. [EDIT] I wanted to correct myself. Slic3r in Pronterface does have a 3d preview. You have to click and drag on the yellow grid and it will rotate. Nice...

If you really want to blow your mind play with Skeinforge. It's hard to get going with it but it's the most configurable slicer I've seen.

Anyway, I don't mean to complicate your diagnosis. Just wanted to mention some of the workflow I took until I got things settled and working well.

Here's what I'd do. Using Slic3r the way you have been, try to print a cube. If that fails, then try printing it with another slicer like Cura or KISSlicer and see if anything changes. If the cube looks good, then it's likely a poorly configured Slic3r profile that you have going. If it fails the same way, then it's likely to be fundamental issues with the calibration of the printer itself.

I've attached a torture test I got from Thingiverse. I printed it with 4 different slicers and the photo is of the one using KISSlicer. Of all the photos I've seen on the web of this torture test, this is one of the cleanest I've seen. I'm really getting good results.



KISSlicer_TowerTorture.jpg

[KDog]

Have you done a full calibration yet? Make sure that all your axis are moving the exact distance you tell them too. Also, make sure you are extruding the correct amount of filament. It looks like you are skipping steps. The most common problem for this is loose belts. Your belts should be so tight that they make a noise when you pluck them. Another thing to do is go over all your screws and make sure they are nice and tight. Any vibration from loose screws will cause alignment issues. Lastly, make sure all your bearings are really tight in their holders. If these can flex at all, your smooth rods will sag as you reach the end of your axis.

Have fun,

KDog

[beerdart]

Rob we have not tried KISS are there any strange settings we should look at? We use Cura 14 with great success I really like the ability to move/rotate the part and the bed sink is a nice feature. The support is also easy to remove from complex areas.

[RobH2]

No, no strange settings that you can't figure out. It does have a nice "quality" slider that you can just drag back and forth after setting up the custom 'max' and 'min' values (or use the defaults). One oddity, it won't print a skirt more than one line. It's free so give it a try. It just makes the cleanest prints I've ever gotten, hands down.